FIG. 3 is a partial sectional view of a conventional speaker. As shown in FIG. 3, the conventional speaker is configured in that voice coil body 2A movably disposed in magnetic circuit 1A is connected to the inner rim of diaphragm 3A, and the outer rim of diaphragm 3A is connected to frame 5A via edge 4A, and further, the rear face of diaphragm 3A is connected to frame 5A via suspension holder 6A and edge 7A. Also, the protruding shapes of edge 4A and edge 7A are opposed to each other in direction to make the vertical excursion of diaphragm 3A vertically symmetrical, thereby reducing distortion in the speaker.
As the preceding technical document information with respect to the invention of the present application, for example, Patent Document 1 is commonly known.
Since the speaker shown in FIG. 3 uses suspension holder 6A which supports diaphragm 3A, it is increased in weight, but it will not become a big problem as a woofer that applies a great output. However, as a mid-range and a full-range speaker, the heavy weight becomes a problem of being low in driving efficiency.    [Patent Document 1] Japanese Laid-open Patent 2004-7332